Expired delegated prefix renewal

[athanp]

What exactly happens when a delegated IPv6 prefix expire? Does dhcpcd take care of updating it?
My ISP offers /56 dynamic prefix that is delegated via dhcpcd to the local network interface (bridge0).
Many times prefix expires without dhcpcd taking any action to renew it, leaving the local network without IPv6.

Have I missed something in the dhcpcd configuration or is some kind of bug?

System: FreeBSD 14.1.release, dhcpcd 10.1.0 port

dhcpcd.conf

noipv4
noipv4ll
ipv6only
noipv6rs
release
background
vendorclassid

duid
allowinterfaces ng0
nohook test,resolv.conf,hostname,ntp.conf

option rapid_commit,interface_mtu,classless_static_routes
nooption domain_name_servers,domain_name,domain_search,host_name
require dhcp_server_identifier

interface ng0
  ipv6rs
  iaid 1
  ia_pd 1 bridge0/0

[perkelix]

I'm wondering the same. Since 10.1.0 I'm getting a lot of "router expired" log messages.

Jan 07 02:27:17 p8h61 dhcpcd[948]: enp4s0: fe80::bb: router expired
Jan 07 02:27:17 p8h61 dhcpcd[948]: enp4s0: part of a Router Advertisement expired

As far as I can tell, dhcpcd makes no attempt to restart router discovery when that happens. Today it resulted in a full night without any IPv6 connectivity. Fixing it required manually restarting dhcpcd in the morning. Not good.

[athanp]

The fact that dhcpcd makes no attempt to automatically restart router discovery or delegated prefix renewal when for whatever reason it has been lost is really killing me.
Having a dynamic prefix, very often even before its lifetime expires, it gets invalidated and as a result dhcpcd does not attempt to renew it and the system is left without IPv6 connectivity.

[perkelix]

IMHO, an expired RA should be treated the same as an unreachable router already is: trigger a send RS.